Cellulases, cellulose (highly-polymerized β-1,4-glucan)-degrading enzymes, generally include cellobiohydrolase (targeting mainly crystalline cellulose) and endo-1,4-β-endoglucanase (targeting mainly amorphous cellulose). For the generation of cellulosic bio-energy, it is important to identify highly active cellulases to improve the efficiency of cellulose decomposition.